Effect of Pulse Beetle (Callosobruchus maculates L.) Infestation on Quality of Pigeonpea Seed

Abstract

The pulse beetle, Callosobruchus spp. is the major storage pest which attack and causes damage to almost all the pulses and affect the germination. Laboratory experiments were conducted to study the effect of Callosobruchus maculatus infestation on seeds of pigeonpea (var. SRG-09) at different days of interval (5, 10, 15 20, 25 and 30th days) at the temperature of 300C and 65 per cent relative humidity. The results of the experiments showed that the number of days of exposure is directly proportional to the level of insect attack. The early stage larvae did not cause much damage to the seed initially. The damage level of seeds was increasing as larva grows inside. The larva was observed in 80 per cent of the seeds on 10th day. Cent per cent infestation of seeds was observed on 20th, 25th day with larvae or pupae and on 30th day with adults. It was also observed that no seed was infested in control with any stage of the insect. The increase in moisture content was observed to the tune of 23.50 per cent due to infestation of larval / pupal stage of bruchid on 30th day. Vigour index also decreased significantly when the seeds were exposed more number of days and it was 61.5 on 30th day.